The present-day helicopters must have a high ratio of horsepower to gross weights because inherently the lift capability of the rotary wing is low; typically for each horsepower applied less than twenty pounds can be lifted, even with the aid of "ground effect" and at sea level air density, and considerably less at higher altitudes. The net payload and range of helicopters are thus severely limited and their fuel consumption is comparatively high. Conventional fixed-wing airplanes, which carry considerably greater useful loads than helicopters can in relation to the horsepower employed, have, however, other inherent limitations consequent upon their design, such as high landing speeds. While present day aircraft are severely restricted in performance by their necessary dependence upon their relatively fragile wings for support.
U.S. Pat. No. 4,202,518, issued May 13, 1980, describes an "Air-Borne Support and Lift Mechanism Adapted to Aircraft". This invention contemplated a relatively Planiform, normally horizontal upper surface of an aircraft, provided with one or more shallow cylindrical recesses or wells. In each of the wells, a horizontal disc is rotatably mounted. This disc has its spindle coaxial with the well and passes through and extends downwardly below the sealed well bottom. The disc is powered for rotation. The nether surface of the discs are fitted with thin blades near the outer rim to turn with minimum clearance above the sealed horizontal well bottom surface. The upper surface of the disc is flat, domed or flat and may comprise symmetrically and generally radially located cambered convexities. The leading edge of the convexity is rounded but somewhat steeper and shorter than the trailing portion. The assembly of this invention allows the disc to turn at normal speed while a steady upward impulse is transmitted to the aircraft structure. In this invention, for any given horsepower input, the lift produced by the configuration compares favorably with the lift produced by a conventional helicopter rotor driven by equal horsepower.
In this invention, through action or interaction of one or more of various causes, an area of lowered air pressure is created over the configuration and extends over the surrounding top deck of the aircraft. On the under body of the aircraft structure, subjacent to the well, an undisturbed air exerts ambient pressure upward. When the unbalanced upward pressure difference exceeds the downward pull of gravity upon the aircraft, the latter is borne upward; when they are in balance, it hovers; when the unbalanced upward thrust is less than the pull of gravity upon the aircraft, the latter descends. The lift action of this invention is, in general, independent of translational movement of the aircraft. When translational movement is present, the same pressure differences persist. Proper aerodynamic conformation of the aircraft enables it to obtain increasing lift as its translational speed increases.
In U.S. Pat. No. 4,202,518, an alternative embodiment is also specified and designated as "spinlift". This comprises an upper, relatively horizontal, vehicle surface called the top deck. The top deck is provide with one or more shallow cylindrical recesses or wells. In each well, a disc is rotatably mounted. A spindle powers this disc for rotation. The disc has a restricted peripheral clearance within the well. The generally flat nether surface of the disc is fitted with thin blades near the outter rim to turn with minimum clearance above the sealed horizontal well bottom surface. The upper surface of the disc is substantially flat, or uniformly dished, or lense-shaped. The upper surface of the disc is preferably set slightly below the level of the surrounding top deck. Variations in the lift effort generated is regulated at will by the operator of the aircraft through changes and disc rotational speed.
The operation of spin lift mechanism is related to the Bernoulli proposition that a surface in motion, relative to an air mass, experiences reduced pressure. A reduced pressure over the upper surface of rotating disc is opposed by a normal ambient air pressure applied upwardly to the subjacent under body of the aircraft, with a consequent net lift effect. Where the rotating upper surface of the disc is exposed directly to stationary superjacent air, the upward movement is measurable and increases with an increase in the speed of rotation of the disc. The closely and circling wall of the well contributes to an effect containment of pressure difference. Concomitant reduced the pressure in the clearance space between the disc nether surface and the upper surface of the well bottom causes the application of a substantial part of the total lift action as "suction" or differential pressure bearing upward on the aircraft body structure subjacent to the well bottom. This minimizes the spindle load.
In the invention of U.S. Pat. No. 4,202,518, additional forms of motive power were invisioned for the forward thrust of the aircraft. Quite obviously, the spin lift mechanism was intent for the vertical take off and landing of the aircraft. Importantly, however, a mechanism for providing thrust to the aircraft was not described in this apparatus. As such, no mechanism was described for allowing air to pass through the rotating disc into a fluid passageway within the aircraft.
The present invention is a further developmental step in this spin lift mechanisms, and its use on flying vehicles.
It is an object of the present invention to provide an aircraft lift mechanism that causes air to pass to an included turbine.
It is an other object of the present invention to provide an aircraft lift mechanism that preserves the lifting benefits of the spin lift mechanism, while creating proper sealing action within the mechanism.
These and other object and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.